16662321 has 32 divisors (see below), whose sum is σ = 27323520. Its totient is φ = 9968832.

The previous prime is 16662319. The next prime is 16662341. The reversal of 16662321 is 12326661.

It is not a de Polignac number, because 16662321 - 2¹ = 16662319 is a prime.

It is a super-2 number, since 2×16662321² = 555265882214082, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (16662311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12346 + ... + 13628.

It is an arithmetic number, because the mean of its divisors is an integer number (853860).

Almost surely, 2^16662321 is an apocalyptic number.

It is an amenable number.

16662321 is a deficient number, since it is larger than the sum of its proper divisors (10661199).

16662321 is a wasteful number, since it uses less digits than its factorization.

16662321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342 (or 1336 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 16662321 is about 4081.9506366442. The cubic root of 16662321 is about 255.4142746990.

Adding to 16662321 its reverse (12326661), we get a palindrome (28988982).

The spelling of 16662321 in words is "sixteen million, six hundred sixty-two thousand, three hundred twenty-one".